The present invention relates to sheet feeding of media and pertains particularly to skew correction for a media feed mechanism.
In printers and other devices that require sheet feeding of media, it is very important to position the image relative to the edges of the media. Some printers use active skew correction during media feeding. When positioning media, many considerations need to be taken into account for optimal performance.
For example, a feeding mechanism needs to provide correct positioning of media for printing. Top skew correction is necessary to line up the image relative to the top of the media. Side skew correction is necessary to line up the image relative to the side of the media. Heavy weight media or sticky media may require greater amount of skew correction. Lighter weight media can be permanently damaged by skew correction that is too rough.
In accordance with the preferred embodiment of the present invention, a media feed mechanism includes a picking device, a first feedroller and a second feedroller. The picking device picks a sheet of media from a media source. The first feedroller moves the sheet of media along a feed media path. During a skew correction phase, the first feedroller rolls in a forward direction feeding the sheet of media forward and the second feedroller turns in a reverse direction preventing the sheet of media from progressing past a nip of the second feedroller. This results in skew correction. After skew correction is performed, the second feedroller turns in the forward direction advancing the sheet of media for printing.